Test case 18 (verification of a client certificate not issued by the
accepted CA) used the Rogue CA certificate as a client
certificate. However, recent gnutls-cli (from GnuTLS git at the time
of this commit) detects the constraint violation and rejects the
certificate, so the test fails before mod_gnutls can check the
certificate. Create a rougue client certificate with correct
constraints to make the test work as expected.